1. Field of the Invention
The present invention relates to a vehicle brake system and, more particularly, to disc brakes for heavy road vehicles.
2. Description of the Prior Art
U.S. Pat. No. 5,205,380 issued to Paquet et al. on Apr. 27, 1993 discloses a disc brake assembly for heavy road vehicles. The disc brake assembly includes a parking or safety brake which is automatically activated when the road vehicle is parked. The parking brake comprises spring acting on a movable plate to urge a brake shoe against a friction surface provided on one face of a disc. A fluid bladder is provided to overcome, when expanded, the force of the spring in order to release the brake shoe from the friction surface of the disc.
Although the parking brake described in the above-mentioned patent is effective, it has been found that there is a need for a new parking brake which is more compact.